4.5-V to 14.5-V Input, 6-A Synchronous Buck, Integrated Power Solution TPS84620 FEATURES DESCRIPTION
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TPS84620
SLVSA43D – OCTOBER 2010 – REVISED OCT 2012
CAPACITOR RECOMMENDATIONS FOR THE TPS84620 POWER SUPPLY
www.ti.com
Capacitor Technologies
Electrolytic, Polymer-Electrolytic Capacitors
When using electrolytic capacitors, high-quality, computer-grade electrolytic capacitors are recommended.
Polymer-electrolytic type capacitors are recommended for applications where the ambient operating temperature is less than 0°C. The Sanyo OS-CON capacitor series is suggested due to the lower ESR, higher rated surge, power dissipation, ripple current capability, and small package size. Aluminum electrolytic capacitors provide adequate decoupling over the frequency range of 2 kHz to 150 kHz, and are suitable when ambient temperatures are above 0°C.
Ceramic Capacitors
The performance of aluminum electrolytic capacitors is less effective than ceramic capacitors above 150 kHz.
Multilayer ceramic capacitors have a low ESR and a resonant frequency higher than the bandwidth of the regulator. They can be used to reduce the reflected ripple current at the input as well as improve the transient response of the output.
Tantalum, Polymer-Tantalum Capacitors
Polymer-tantalum type capacitors are recommended for applications where the ambient operating temperature is less than 0°C. The Sanyo POSCAP series and Kemet T530 capacitor series are recommended rather than many other tantalum types due to their lower ESR, higher rated surge, power dissipation, ripple current capability, and small package size. Tantalum capacitors that have no stated ESR or surge current rating are not recommended for power applications.
Input Capacitor
The TPS84620 requires a minimum input capacitance of 100 μ F of ceramic and/or polymer-tantalum capacitors.
The ripple current rating of the capacitor must be at least 450 mArms.
includes a preferred list of capacitors by vendor.
Output Capacitor
The required output capacitance is determined by the output voltage of the TPS84620. See
for the amount of required capacitance. The required output capacitance can be comprised of either all ceramic capacitors, or a combination of ceramic and bulk capacitors. The required output capacitance must include at least 1x 47 µF ceramic capacitor. When adding additional non-ceramic bulk capacitors, low-ESR devices like the ones recommended in
are required. The required capacitance above the minimum is determined by actual transient deviation requirements. See
for typical transient response values for several output voltage, input voltage and capacitance combinations.
includes a preferred list of capacitors by vendor.
MIN
1.2
3.0
4.0
Table 3. Required Output Capacitance
V
OUT
RANGE (V)
MINIMUM REQUIRED C
OUT
(µF)
MAX
< 3.0
< 4.0
5.5
(1) Minimum required must include at least one 47 µF ceramic capacitor.
200
(1)
100
(1)
47 µF ceramic
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TPS84620 www.ti.com
SLVSA43D – OCTOBER 2010 – REVISED OCT 2012
Table 4. Output Voltage Transient Response
C
IN1
= 2 x 22 µF CERAMIC, C
IN2
= 68 µF POSCAP, LOAD STEP = 3 A, 1 A/µs
V
OUT
(V) PV
IN
(V) C
OUT1
Ceramic C
OUT2
BULK
VOLTAGE
DEVIATION (mV)
1.2
3.3
5
12
4x 47 µF
1x 47 µF
4x 47 µF
1x 47 µF
4x 47 µF
None
330 µF
None
330 µF
None
73
50
63
45
45
3.3
1x 47 µF
4x 47 µF
1x 47 µF
330 µF
None
220 µF
35
80
65
1.5
5
12
3.3
4x 47 µF
1x 47 µF
4x 47 µF
1x 47 µF
4x 47 µF
1x 47 µF
4x 47 µF
1.8
5
None
220 µF
None
220 µF
None
220 µF
None
60
60
45
50
90
72
80
12
3.3
1x 47 µF
4x 47 µF
1x 47 µF
4x 47 µF
1x 47 µF
220 µF
None
220 µF
None
100 µF
67
60
60
108
93
2.5
3.3
5.0
5
12
5
12
5
12
4x 47 µF
1x 47 µF
4x 47 µF
1x 47 µF
2x 47 µF
1x 47 µF
2x 47 µF
1x 47 µF
1x 47 µF
1x 47 µF
1x 47 µF
1x 47 µF
None
100 µF
None
100 µF
None
100 µF
None
100 µF
None
100 µF
None
100 µF
110
140
100
200
150
180
150
100
92
88
80
160
PEAK-PEAK (mV)
132
120
119
214
186
98
100
180
142
160
70
160
130
115
120
137
90
117
85
109
220
280
200
400
300
360
300
200
180
174
157
320
75
110
75
110
100
110
80
110
75
110
100
100
100
100
130
100
130
RECOVERY TIME
(µs)
70
75
70
75
70
80
70
80
110
80
75
80
70
80
70
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Product Folder Links: TPS84620
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TPS84620
SLVSA43D – OCTOBER 2010 – REVISED OCT 2012
Table 5. Recommended Input/Output Capacitors
(1)
VENDOR
Murata
TDK
Murata
Sanyo
Kemet
Sanyo
Sanyo
Kemet
Kemet
Sanyo
Sanyo
SERIES
X5R
X5R
X5R
POSCAP
T520
POSCAP
POSCAP
T530
T530
POSCAP
POSCAP
PART NUMBER
GRM32ER61E226K
C3225X5R0J476K
GRM32ER60J476M
16TQC68M
T520V107M010ASE025
6TPE100MI
2R5TPE220M7
T530D227M006ATE006
T530D337M006ATE010
2TPF330M6
6TPE330MFL www.ti.com
WORKING
VOLTAGE
(V)
CAPACITOR CHARACTERISTICS
CAPACITANCE
(µF)
ESR
(m Ω )
(2)
16
6.3
6.3
22
47
47
2
2
2
16
10
6.3
2.5
6.3
6.3
2.0
6.3
68
100
100
220
220
330
330
330
7
6
10
6
50
25
25
15
(1) Capacitor Supplier Verification
Please verify availability of capacitors identified in this table.
RoHS, Lead-free and Material Details
Please consult capacitor suppliers regarding material composition, RoHS status, lead-free status, and manufacturing process requirements.
(2) Maximum ESR @ 100kHz, 25°C.
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